Freewheeling device



Feb. 5, 1946. F. w. SCHWINN 2,394,112

' FREEWHEELING DEVICE Filed June 15, 1944 2, Sheets-Sheet 1 my, 8W

Patented Feb. 5, 1946 UNITED STATES PATENT OFFICE l 1,394,112 V FREEWHEELING DEVICE I Frank WQSchwinn, Chicagodll. Application une 15, 1944, Serial No. 540,377

" 3 Claims. (01.192-64) The present invention relates to freewheeling devices, and is'particularly concerned with freewheeling devices adapted to be used upon bicycles and various other types of cycles.

One of the objects of the invention is the provision of an improved freewheeling device of the type adapted to be used with a plurality of sprockets in which the construction is so improved that the size may be materially reduced and arela tively smaller sprocket, such as, for example, a fourteen tooth sprocket, may be mounted upon it.

Another object of the invention is the provision of an improved construction for freewheeling-devices in which the sprocket support is self -tightening, but the sprockets are provided with an improved means for mounting so that they can readily be removed and thegear ratio can be changed manufactured at a minimum cost, and sturdy, so that it may be used for a long period of time without necessity for-repair or replacement of any of its parts.

Other objects and advantages of the invention will be apparent from the following description and the accompanying drawings, in which similar characters of reference indicate similar partsthroughout the several views.

Referring to the drawings, of which there are two sheets,

Fig. 1 is a fragmentary sectional view, taken upon a line passing through the axis of the wheel shaft, showing the details of construction of my improved freewheeling device;

Fig. 2 is a fragmentary sectional view, taken on the plane of the line 2-2 of Fig. 1, looking in the direction of the arrows;

Fig. 3 is another sectional view, taken on the plane of the line 3-3 of Fig. 1, looking in the direction of the arrows;

Fig. 4 is a fragmentary sectional view, taken on the plane -of the line 4-4 of Fig. 1, looking in the direction of the arrows.

Referring to Fig. 1, I0 indicates in its entirety the freewheeling device, which is shown in conwhich is simple in construction, adapted to be "metal member l4 having a tubular body portion I5, which is provided at one end with an enlarge-'- ment [6 having an integral spoke flange l1. 4 The enlargement I6 is preferably provided with a cylindrical recess or bore 18 for receiving the ball bearing race I9. The ball bearing race l9 may have a plane end surface 20 and an outer cylindrical surface 2|, and is complementary to the recess l8 and has a frictional fit therein.

The ball bearings are preferably of the selfaligning type so that the race I9 is provided with a groove 22 partially circular in cross section, located opposite the juncture of the two surfaces 20, 2| for receiving the balls 23. The race I9 may also have an outer plane surface 24, which terminates short of the end of the recess l8 so that the recess is also adapted to receive an oil seal 25, the outer surface of which is flush with the outer face 26 of the enlargement IS.

The oil seal 25 may consist of a pair of angular annular members 21, 28, housing an annular memsection, but which has its aperture 36 slightlysmaller than the cylindrical surface 31 on the cone 35, which it engages.

The outer cylindrical flange 33 of the oil seal 25 is of such size that it has a tight frictional'fit in the cylindrical bore 18 in which it is driven home against the end surface 24 of race IS.

The shaft I3 is provided with the usual threaded end portions 38, 39 for receiving the nuts 4ll43. The ball bearing cone 35 consists of a tubular metal member having a non-circular end portion 44 for engagement with a wrench and a cylindrical through bore 45, which is unthreaded and which passes the threaded portion 38.

Its external surface 31 may be cylindrical, but at its inner end it is provided with an annular groove 45 that is preferably curved on a radius substantially larger than that of the .balls 23,

of a bicycle, the two (Fig. 2).

while the groove 22 is curved on substantially the same radius as that of the'balls 23.

The nut 4| holds the cone race member 35in engagement with the balls 23 under a predetermined pressure when the opposite cone 35 is engaged by the nut 42, and the right cone member 35 engages the balls 23 at this end.

The nuts 4|, 42 are locked in place by engage- V ment with the rear forks II and the nuts 45, 43.

The opposite end of the tubular-member l5,is provided" with] a radially extending flange 41, which is curved at 48 and provided with an tion, but are provided on their inner faces, ad-

supplementary race ring I8, 19. The race rings 8, 19 are substantiall rectangular in cross secjacent the ratchet flange 13, with a beveled surface 85 so'as to eliminate any possibility of interference with the ratchet.

The opposite surfaces of these race rings 18, i9 engage the balls 5|, 8|, which form the parts of a ball bearing structure for rotatably support-.

ing the; ratchet member .712 on the. hub M. The balls (it are; engaged on the: left side. (Fig. 1) by 7 another race member 82, which has a substanaxially extending portion 49 for supporting the? spoke flange 50. This provides a recess 5| for housing a portion of the free-wheelingdevice.

v The tubular member. I5 is preferably rovided. with a larger counter-bore 52 at its right end and with a smaller threaded bore 53 for receiving the complementary threaded end 54 of a tubular bearing member 55. V The bearing member 55 has in that it has a similar groove. 22,,a ylindrical outer surface 2 and a plane face 24. In order to drive the tubular member 55 into threaded;

1 engagement with the. tubular member t5., the

bearing member 55. also has the end of its bore 57 formed with a pair of radiall extending milled recesses 53,. These. recesses are deep enough to receive a special wrench by means of which the tubular member 55is driven home into tight engagement with the member-l5. J The. bearing member 55 is also formed with a reduced cylindrical portion 59 and an annular shoulder 60 serving to engage the ball bearings EL w The cylindrical portion 59 is formed with a radial bore 52 for receiving the helical compression spring 63, which engagesthe pawl 64 member, such as steel, having a plane outer face 65 and a curved inner surface 66, which tapers to a point 61.

The spring. 83 engages its plane inner face and at its end opposite to the point Bi; it is provided with a partially cylindrically curved. sur-' face 58. The cylindrical surface 68 fits in a complementary recess 69 .in the bearing member 55, and the surface 39 is a part ofthefsurface of a recess 75, which is complementary to the inner surface of the pawl 65, so that the pawl is adapted to be received in the member 55 Sufliciently to pass the inwardly extending teeth "H of' a ratchet member". Q I.

The teeth H are carried by van inwardly extending flange 13 on the ratchet member 12', .and they are provided with the abrupt surface or shoulders 74 which extend substantially radially and with the'diagonally extending camming surffaces 15, which have their major dimension extending peripherally of the ratchet. H

Ally number of spring pressed pawlsrnay be 3 used, but they are preferably'symmetrically arranged so as to exert a balanced'torquefand they are preferably reduced to a minimum which will accomplish this result, such as two; because the friction is increased by the use of each additional pawl. V V W The ratchet flange I3 is formedEat each of its sides with anannular shoulder 16, 11, and each annular surface 16, 11 engages the side of a The pawl 84 may consist of a metal.

ti-ally cylindrical bodyprovided with a cylindrical surface 83 for engaging the balls 6!.

A radial flange 84 has an annular surface 85 serving as athrust surface for the balls BLYand the race member 82 has a cylindrical bore 85 with a frictional fit on the bearing member 55.

At. its. left end this race member 52 may have a reduced cylindrical portion 87 for engaging a complementary bore in a. felt; ring 38, which serves as an oil seal for'this end of the freewheelin device. a.

The felt ring engaged on its right side by an annular shoulder 89 and on its left side. (Fig.

1) by a machined surface 95 0 the. flange .41'.

Itis retained in place and slightly compressed by the innerv cylindrical surface ill on the ratchet member 12, this cylindrical surface also serving to confine the balls 61'. v

The length of the ratchet member 12 is suffici'ent so that. it projects beyond the balls 23 sufficiently to. provide space for another oil seal 25, which may be similar in structure and similarly mounted with respect to the cone race 35, and ratchet member'l2, as described, with respect to the left end of the structure in Fig. l. j

Theiratchet member 12 is provided at its left end with a reduced threaded portion 92 for receiving a nut 93 that: serves to confine and secure the sprockets at this end. Extending toward'the right in Fig. 1 from the threaded portion 92'the external surface 94 of. ratchet member 12 is noncircular in form, such as, for example, octagonal or hexagonal. I

In Fig. 3 the present embodiment is shown to be octagonal, and the sprockets 35-43! are all provided with the complementary octagonal apertures 98 for receiving thisnon-circular por- 7 'tion' of the ratchet member 12. Spacers 38 are interposed between'the nut 93 and thesprocket and between each pair of sprockets," and the right end of the ratchet member 'IZhas'a-re'duced threaded portion 99' for receiving a nut i551 v Thespro'ckets and spac ers are clamped on the ratchet member 12' byimea'ns of the nuts ss and I00; and in every case the direction of the thread used on this membenas wellas the threads at 53, 54, is preferably such'that when the loadis applied to the sprocket by means of a chaimsu'ch as the chain NH, the sprocket will continue to tighten itself. In thread. The operation of the present freewheeling :device is asfollo'ws: By removing the ring nut I93 the sprockets can be readily removediand'replaced with sprockets of another'sizefi This overcomes one of the principal difioulties experienced with the freewheeling devices of the prior artl f-The torque strain on these sprockets is considerable,- and would beexcessive'for theuse' of' a' keyi-way device, which mightalso require enlargement of the sprockets to provide suitable' str-ength;

All of the parts of the bearing are. preferably made of suitable steel, and the ratchet" member Fig l this requiresa right Y 12 may be made of octagonal bar steel. When torque is applied to any one of the sprockets to which the chain happens to beattached in a forward or right hand direction, the sprocket the wheel continues to rotate, due tothe momen-' tum or due to the fact that the vehicle isproceeding downhill, the diagonal camming surfaces 15 on the ratchet member cam the pawl 64 inward and permit the wheel to run ahead of the sprockets.

One of the most important advantages of the present invention is that the device can be made more compact than the devices of the prior art so that a small fourteen-toothed sprocket can be used, due to the particular structure and arrangement of the parts, whereas the smallest sprocket that could be used on the devices of the prior art is a sixteen-toothed sprocket.

The present device operates with a minimum amount of friction, and it may be kept suitably lubricated at all times because its oil seal and structure are such as to retain the grease in place and to maintain adequate lubrication.

While I have illustrated a preferred embodiment of my invention, many modifications may be made without departing from the spirit of the invention, and I do not wish to be limited to the precise details of construction set forth, but desire to avail myself of all changes within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

1. In a bearing structure for cycles or the like,

and pawl support and said sprocket supportin member.

2. In a bearing structure for cycles or the like,

the combination of a hub member comprising a tubular body having a threaded counterbore, a

combined race and pawl support having a complementary threaded tubular portion threaded into said hub, said combined race and pawl support being provided with a bore for passing a the combination of a hub member comprising a latter bore, and a pawl engaged by said spring,

a sprocket supporting member rotatably supported upon said combined race and pawl support, said sprocket supporting member having an external polygonal surface, and a sprocket fixedly mounted upon said latter surface, said sprocket-supporting member having an inwardly extending flange provided with ratchet teeth for engaging said pawl, said latter fiange serving as a thrust flange for engaging anti-friction bearing members confined between said combined race shaft, a radially extending bore in said combined race and pawl support, a helical spring in said latter bore, and a pawl engaged by said spring, a sprocket supporting member rotatably supported upon said combined race and pawl support, said sprocket supporting member having an external polygonal surface, and a sprocket fixedly mounted upon said latter surface, said sprocketsupporting member having, an inwardly extending flange provided with ratchet teeth for engaging said pawl, said sprocket supporting member having a bore and extending outwardly beyond said combined race and pawl support, ball bearings engaging said combined race and pawl support, a'second race engaging inside said ball bearings, and a resilient felt oil sealing member carried by said sprocket supporting member and engaging said latter race.

3. In a bearing structure for cycles or the like, the combination of a hub member comprising a tubular body having a threaded counterbore, a combined race and pawl support having a complementary threaded tubular portion threaded into said hub, said combined race and pawl supa sprocket supporting member rotatably sup ported upon said combined race and pawl support, said sprocket supporting member having an external polygonal surface, and a sprocket fixedly mounted upon said latter surface, said sprocketsupporting member having an inwardly extending flange provided with ratchet teeth for engaging said pawl, said sprocket supporting member having a bore and extending outwardly beyond said combined race and pawl support, ball bearings engaging said combined race and pawl support, a second race engaging inside said ball bearings, and a resilient felt oil sealing member carried by said sprocket supporting member and engaging said latter race, saidfelt oil sealing member being confined between two angular annular members which are frictionally engaged with each other and by said sprocket supporting member.

FRANK W. SCHWINN. 

